Information display apparatus and spatial sensing apparatus

ABSTRACT

An information display apparatus and a spatial sensing apparatus for the information display apparatus are provided, the information display apparatus enabling the selection/change of the lot of display images in small point-of-view motion so that an interactive function for a driver is achieved. An information display apparatus displaying information onto a vehicle includes: an information display apparatus displaying image information onto an image display region on a forward part of a driver seat of the vehicle; and a spatial sensing means detecting positional information of instruction made by a driver in a spatial region between the driver seat and the displayed image display region, and the information display apparatus includes a means displaying the instruction made by the driver onto the image display region on the forward part in response to the positional information of the instruction made by the driver, detected by the spatial sensing means.

TECHNICAL FIELD

The present invention relates to an information display apparatus thatprojects information containing images onto a windshield glass ofso-called vehicle such as a car, a train and an airplane moving whilepeople are loaded therein, and, more particularly, relates to aninformation display apparatus having an interactive function used by adriver or others and relates to a spatial sensing apparatus forachieving the information display apparatus.

BACKGROUND ART

So-called Head-Up-Display (HUD) apparatus has been already known in, forexample, the following Patent Document 1, the head-up-display apparatuscreating virtual images by projecting image light onto a windshieldglass of a car to display traffic information such as route informationand traffic congestion information and car information such as a fuellevel and a coolant temperature.

RELATED ART DOCUMENT Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open Publication    No. 2015-194707

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

For such a type of information display apparatus, downsizing isnecessary in order to arrange the HUD apparatus main body between asteering in front of a driver seat and a windshield glass, and besides,so-called interactive function that enables operation in such a mode ascreating interaction while making a user view a projected screen isnecessary.

In the above-described head-up-display apparatus according to therelated art, although a technique for the downsizing has been disclosed,the interactive function has not been described. Particularly, atechnique has not been totally disclosed, the technique being an issueon the HUD apparatus and enabling the interactive operation for a screenprojected on a space between the steering in front of the driver seatand the windshield glass.

A purpose of the present invention in an information display apparatusthat projects information containing images onto a windshield glass of avehicle is to provide an information display apparatus enabling aninteractive function used by a driver and provide a spatial sensingapparatus for achieving the information display apparatus.

Means for Solving the Problems

The present invention has been made in order to achieve theabove-described purpose. As one example to be cited, the presentinvention relates to an information display apparatus that displaysinformation onto a vehicle, the information display apparatus includesan information display apparatus that displays image information onto animage display region on a forward part of a driver seat of the vehicleand a spatial sensing means that detects positional information ofinstruction made by the driver in a spatial region between the driverseat and the displayed image display region, and the information displayapparatus includes a means that displays the instruction made by thedriver onto the image display region on the forward part in response tothe positional information of the instruction made by the driver,detected by the spatial sensing means.

In the present invention, note that the information display apparatusmay include a virtual-image optical system that displays a virtual imageonto the forward part of the vehicle by causing the windshield glass ofthe vehicle to reflect light emitted from this apparatus, theinformation display apparatus may include a practical-image opticalsystem that displays a practical image by scanning the windshield glassof the vehicle with the light emitted from this apparatus, or theinformation display apparatus may include a direct-view type imagedisplay apparatus using an instrument panel of the vehicle.

Further, the present invention relates to a spatial sensing apparatusfor achieving the above-described information display apparatus, and aprovides a spatial sensing apparatus of the information displayapparatus that is configured so that a plurality of a pair of a lightemitting element and an optical element are linearly arranged, the lightemitting element creating a collimated light flux from a light fluxemitted from a light source and the optical element being made of alight-collecting lens element that receives a reflected light flux onobstacles among the light flux from this light emitting element.

Effects of the Invention

In an information display apparatus that projects information containingimages onto a windshield glass of a vehicle, the present invention canprovide an information display apparatus enabling selection/change ofcar control and a lot of display images such as a car control contentand navigation information, etc., and enabling an interactive functionoperated by a driver, and provide a spatial sensing apparatus forachieving the information display apparatus.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of an information displayapparatus having an interactive function and peripheral apparatuses ofthe information display apparatus according to a working example of thepresent invention;

FIG. 2 is a schematic cross-sectional configuration diagram showing theinformation display apparatus, a windshield glass and a point-of-viewposition of a driver in a working example;

FIG. 3 is a schematic explanatory diagram of an image display positionin a working example;

FIG. 4 is a schematic explanatory diagram of another image displayposition in a working example;

FIG. 5 is a schematic diagram for explaining a configuration for use inachieving an interactive function in a working example;

FIG. 6 is a schematic diagram for explaining an interactive function ina working example;

FIG. 7 is a first explanatory diagram for explaining a principle of aspatial sensing apparatus;

FIG. 8 is a second explanatory diagram for explaining the principle ofthe spatial sensing apparatus;

FIG. 9 is a diagram for explaining difference in a curvature radius of awindshield glass in a working example;

FIG. 10 is a characteristic diagram showing a reflectance with respectto an incident angle of different polarized light on a glass in aworking example;

FIG. 11 is a top view of a car on which an information display apparatusis mounted in a working example;

FIG. 12 is a characteristic diagram showing a reflectance of areflective material applied, adhered or pasted on a windshield glass ina working example;

FIG. 13 is a schematic configuration diagram of a virtual-image opticalsystem of an information display apparatus in a working example;

FIG. 14 is a basic configuration diagram of a projection opticalapparatus in a working example;

FIG. 15 is a schematic configuration diagram of a bi-axial MEMS elementin a working example;

FIG. 16 is an explanatory diagram for explaining an outline of a lightflux scan using a MEMS element in a working example;

FIG. 17 is an explanatory diagram for a first scanning state of laserlight with which a free curved mirror is scanned in a working example;

FIG. 18 is light spectra of a light source of a light scanning apparatusin a first scanning state in a working example;

FIG. 19 is a black body locus and an isotemperature line diagram;

FIG. 20 is a diagram showing a chromaticity table of the light of thelight source of the light scanning apparatus in the first scanning statein a working example;

FIG. 21 is an explanatory diagram for a second scanning state of thelaser light with which the free curved mirror is scanned in a workingexample;

FIG. 22 is light spectra of a light source of a light scanning apparatusin a second scanning state in a working example; and

FIG. 23 is a chromaticity table of the light of the light source of thelight scanning apparatus in the second scanning state in a workingexample.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, working examples of the present invention will be describedin detail with reference to drawings and others.

First, FIG. 1 is a schematic configuration diagram of an informationdisplay apparatus having an interactive function and peripheralapparatuses of the information display apparatus according to a workingexample of the present invention. Here, as one example, an informationdisplay apparatus that projects images onto a windshield glass of a carwill be particularly explained. FIG. 1(A) is a cross-sectionalperspective view of the information display apparatus, and FIG. 1(B) isa schematic configurational block diagram of the peripheral apparatuses.

FIG. 1(A) is a conceptual diagram of a cross-sectional surface of avehicle body in which a numerical symbol 45 indicates a vehicle bodywhile a numerical symbol 6 is a windshield glass that is aprojection-receiving member. A HUD apparatus 100 is an apparatus thatdisplays various types of information reflected as a virtual image bythe projection-receiving member 6 (that is an inner surface of thewindshield glass in the present working example) in order to form thevirtual image on a forward part of a subject vehicle on a line of sight8 of a driver. Note that the projection-receiving member 6 may be anymember as long as being a member on which the information is projected,and may be not the above-described windshield glass but a combiner. Thatis, The HUD apparatus 100 of the working example may be any apparatus aslong as forming the virtual image on the forward part of the subjectvehicle on the line of sight 8 of the driver and allowing the driver tovisually recognize the virtual image, and the information displayed asthe virtual image includes, for example, vehicle information andinformation of front scenery, an image of which is captured by a camera(not illustrated) such as a monitoring camera, an around viewer cameraand others.

The HUD apparatus 100 is provided with the image display apparatus 4that projects the image light for use in displaying the information andlenses 2 and 3 that are the correcting optical elements for use incorrecting distortion and aberration caused when the virtual image isformed by the concave mirror 1 using the image displayed on this imagedisplay apparatus 4, the lenses being provided between the image displayapparatus 4 and the concave mirror 1.

The HUD apparatus 100 includes a controlling apparatus 40 that controlsthe image display apparatus 4 and a backlight source 10. Note thatoptical components including the image display apparatus 4, thebacklight source 10 and others configure a virtual-image optical systemdescribed below, and include a concave mirror 1 having a concave shapethat reflects the light. The light that has been reflected on thisconcave mirror 1 is reflected on the windshield glass 6 and goes to theline of sight 8 (that may be so-called Eyebox that is a driver'scorrectly-viewable point-of-view range) of the driver.

As the above-described image display apparatus 4, for example, note thatnot only an LCD (Liquid Crystal Display) having a backlight but also aself-luminescent VFD (Vacuum Fluorescent Display) and others are cited.

Meanwhile, the image may be displayed on a screen by a projectionapparatus in place of the above-described image display apparatus 4, becreated as the virtual image by the above-described concave mirror 1, bereflected by the windshield glass 6 that is the projection-receivingmember, and be headed to the point of view 8 of the driver 8. Such ascreen may be made of, for example, a micro lens array obtained bytwo-dimensionally arranging micro lenses.

More specifically, in order to reduce the distortion of the virtualimage, a shape of the concave mirror 1 may have a relatively smallcurvature radius so as to increase a magnification power in an upperportion (a region that reflects the light rays on a lower portion of thewindshield glass 6 having a relatively short distance to the point ofview of the driver) shown in FIG. 1 (A) but have a relatively largecurvature radius so as to decrease the magnification power in a lowerportion (a region that reflects the light rays on an upper portion ofthe windshield glass 6 having a relatively long distance to the point ofview of the driver). Alternatively, more favorable correction is alsoachieved by tilting the image display apparatus 4 from the optical axisof the concave mirror to correct the difference in the virtual-imagemagnification, which results in the reduction in the distortion itself.

Next, in FIG. 1 (B), from the navigation system 60, the controllingapparatus 40 acquires various types of information such as a speed limitand the number of lanes of a road corresponding to a current position atwhich the subject vehicle is running, a travelling-scheduled route ofthe subject vehicle set in a navigation system 60 or others asforeground-scenery information (that is information displayed as thevirtual image on the forward part of the subject vehicle).

A driving assistance ECU62 is a controlling apparatus that achievesdriving assistance control by controlling a driving system and a controlsystem in accordance with obstacles detected as a result of monitoringperformed by a surrounding monitoring apparatus 63. The drivingassistance control includes publicly-known techniques such as a cruisecontrol system, an adaptive cruise control system, a pre-crash safetysystem and a lane keeping assist system.

The surrounding monitoring apparatus 63 is an apparatus that monitors asurrounding state of the subject vehicle, and is, as one example, acamera that detects an object existing in surroundings of the subjectvehicle on the basis of an image acquired by capturing an image of thesurroundings of the subject vehicle, an exploration apparatus thatdetects an object existing in surroundings of the subject vehicle on thebasis of a result of transmission/reception of exploration waves, andothers.

As the foreground-scenery information, the controlling apparatus 40acquires the information (such as a distance to a vehicle running ahead,a direction of the vehicle running ahead, positions of obstacles andtraffic signs and others) from such a driving assistance ECU62. Further,to the controlling apparatus 40, an ignition (IG) signal andsubject-vehicle state information are input. The “subject-vehicle stateinformation” of such information is information acquired as the vehicleinformation, and includes alert information showing, for example,occurrence of a predetermined abnormal state of a fuel level of aninternal combustion engine, a coolant temperature or others. And, theinformation also includes an operational result of a turn signal and arunning speed of the subject vehicle, and besides, shift-lever positioninformation and others.

An image signal from the controlling apparatus 40 described above is theimage information corresponding to the state and the ambientsurroundings of the car, and is selectively suitably displayed by theHUD apparatus 100 that is the first information display apparatus foruse in overlapping the virtual image with the background practical viewviewed by the viewer, displayed by the projection optical apparatus 220that is the second information display apparatus for use in overlappingthe practical image with the foreground view, and displayed by thedirect-view type instrument panel 42 that is the third informationdisplay apparatus, so that point-of-view motion performed during thedriving by the driver who is the viewer is reduced. Note that thiscontrolling apparatus 40 is activated by the input of the ignitionsignal. The configuration of the entire system of the informationdisplay apparatus according to the present working example has beendescribed above.

FIG. 2 is a schematic cross-sectional configuration diagram showing theinformation display apparatus, a windshield glass and a point-of-viewposition of a driver in the present working example. FIG. 3 is aschematic explanatory diagram of an image display position in thepresent working example, which is a schematic diagram in which thewindshield glass 6 is viewed from the driver seat.

As shown in FIGS. 2 and 3, the present working example includes an imagedisplay region 1 (a) near a center of the windshield glass 6 that is aforward surface of the steering 43, an image display region 2(a) on thelower portion of the windshield glass 6 and an image display region 3(a)over the instrument panel 42.

The information display apparatus in the present working example cansuppress the point-of-view motion by causing the above-described HUDapparatus 100 to provide the viewer with a virtual image having avirtual-image distance of 8 m and a size that is equal to or larger than40 inches while using, as a reflection surface, the image display region1(a) (see FIGS. 2 and 3) near the center of the windshield glass 6 sothat the virtual image is overlapped with the practical scenery that isbeing looked at by the driver during the driving. Note that theinventors have measured change of the point-of-view position of thedriver during the driving in town, and have found that, through apractical measurement, the point-of-view motion is suppressed by 90%when the maximum value of the virtual-image distance is 30 m. Also,during a high-speed driving, it has been found that, through anexperiment, the point-of-view motion can be similarly suppressed whenthe virtual-image distance is set to be equal to or larger than 70 m. Inthis case, a necessary virtual-image size is equivalent to 350 inches.

As described above, the HUD apparatus 100 displaying the virtual imageis used to display this virtual image in the image display region 1(a)for a background region on which the point of view of the viewer is put.On the other hand, in order to overlap the image with the foregroundview that is practically looked at by the driver who is the viewer inthe image display region 2(a), the practical image is projected on thelower portion of the windshield glass by using the projection opticalapparatus 220 that causes the MEMS (Micro Electro Mechanical Systems)elements to perform the scan with a light flux having a specificpolarized wave. In this case, the image display using the MEMS isadvantageous for the projection onto the windshield glass 6 having acurvature because this image display is basically performed in focusfree.

Note that a member having a property of a reflectance against thespecific polarized wave described in detail later, the reflectance beingdifferent from that against other polarized wave, is contained in thelower portion of the windshield glass on which the image is projected,or the member is applied, adhered or pasted on a glass surface insidethe car, so that the image light is effectively reflected so as toorient the practical image to the viewer. In this case, a horizontaldisplay dimension in the image display region 1(a) on the windshieldglass 6 created by the HUD apparatus 100 is smaller than a horizontaldisplay dimension of the practical image displayed by the projectionoptical apparatus 220 because the image light is focused to create thevirtual image on a background part in front of the windshield glass.

Further, through an experiment, it has been verified that virtualthree-dimensional display is achieved by overlapping an image displayregion 2 (b) where the image is overlapped with the foreground view witha part or entire of a background-image display region 1 (b) where thevirtual image is displayed by using the HUD apparatus as shown in FIG. 4in place of the above-described division of the image display regions.When a display position of the virtual image in a deep direction ispartially overlapped with a display position of the practical image inthe deep direction in order to achieve more favorable display, a morefavorable effect has been obtained. And, continuity of the displayedimage has been obtained by the overlap display of the two image displayregions, so that a new effect such as the smoothed point-of-view motionhas been also obtained.

A display position, a display color and a display pitch of the virtualimage projected on the above-described portion near the center of thewindshield glass are suitably selected by a viewing camera 210 for usein viewing a state of the viewer, and not only an image display ofinformation indicating a next operation of a car controlled in anautonomous driving state, such as turning right/left, stoppage oracceleration, but also an image display for attention seeking by usinginformation acquired by sensing a health state of the driver, sleepinessof the same or others are performed. Note that it is unnecessary toalways display such information, and it is desirable to follow a motionof a line of eyes of the driver by using the viewing camera 210 anddisplay the information at a necessary part if needed.

<Interactive Function>

The inventors have found out that, for example, combination use of aspatial sensing apparatus with the above-described information displayapparatus in order to reduce the point-of-view motion and acquire a lotof information achieves an image display apparatus selecting/changing alot of display images such as the control, the control content and thenavigation information of the car in small point-of-view motion byselecting a plurality of images or selecting a switch unit or others, animage of which is displayed. Particularly, the inventors have found outthat achievement of so-called interactive function enabling an operationin a mode allowing a user to have interaction while viewing a projectedscreen is effective to achieve a more convenient and availableinformation display apparatus. A configuration for use in achieving suchan interactive function will be described below.

<Spatial Sensing Apparatus>

A numerical symbol 51 shown in FIG. 1(A) indicates a spatial sensingapparatus corresponding to the instrument panel 42 (the image displayregions 3(a) and 3 (b)) and is arranged close to a display surface, sothat a plurality of images are selected, or a switch unit, an image ofwhich is displayed, is selected to achieve selection for the lot ofdisplay images such as the control, the control content and thenavigation information of the car in the small point-of-view motion.Further, numerical symbols 52 and 53 indicate a spatial sensingapparatus that are arranged in parallel to the spatial sensing apparatus51 so as to enable spatial sensing (corresponding to the image displayregions 1(a) and 2(a) in FIG. 3 or the image display regions 1(b) and2(b) in FIG. 4) also for the positional information in the deepdirection from the steering 43 to the windshield glass 6.

As one example of the spatial sensing apparatus, for example, thespatial sensing apparatus 53 corresponding to the image display region1(a) or 1(b) in FIGS. 3 and 4 will be particularly described here. Asshown in FIGS. 5 and 6, in this spatial sensing apparatus, by freelyoperating/moving the driver's finger (or a bar-shaped object held by thefingers: obstacle) on a spatial region (shown with a dashed line “A” inthe drawings), the driver who is driving the car while viewing theinformation displayed on this image display region can freelyoperate/move an instruction means (pointer) on a screen displayed onthis image display region even when taking the driver seat. Accordingly,a position of this instruction means (pointer) is calculated from, forexample, a detected coordinate position of the finger (obstacle) througha conversion apparatus 531 or others, and is output as positionalinformation of the pointer to the above-described HUD apparatus 100 (seeFIG. 1 or 2).

In this manner, even during the driving, the driver can input thepositional information corresponding to a desirable position of thescreen information to make an instruction of a desirable order by movingthe finger or others to the desirable position of the screen informationin the spatial region shown with the dashed line A while viewing thescreen information displayed on the forward part. That is, the so-calledinteractive function enabling the operation in the mode allowing theuser to have interaction while viewing the projected screen is achieved.

Subsequently, FIG. 7 shows a principle of a configuration and anoperation of the spatial sensing apparatus of the invention of thepresent application. When the finger of the user (such as the driver)moves from a left side to a right side in the drawing, a light flux φ1from a first light source 60 is converted first to asubstantially-collimated light flux by a capacitor optical element 61,is reflected by the moving finger of the user, is collected to become areflective light flux φ3 by a light-collection lens element 65, andreaches a first light receiving unit 64.

At this stage, information of a distance to the finger in a Y-axisdirection is acquired from a temporal difference Δt1 betweenlight-emission time of the first light source 60 and light-receptiontime of the first light receiving unit 64, and, at the same time,information of the position in an X-axis direction is acquired fromabsolute positional coordinates of the first light source 60 and thefirst light receiving unit 64. Then, as shown in this drawing, when thefinger of the user (such as the driver) moves from the left side to theright side in the drawing, a light flux φ4 from a third light source 68is converted first to a substantially-collimated light flux by acapacitor optical element 69, is reflected by the moving finger of theuser, is collected to become a reflective light flux φ6 by alight-collection lens element 73, and reaches a third light receivingunit 72.

At this stage, information of a distance to the finger in the Y-axisdirection is acquired from a temporal difference Δt2 betweenlight-emission time of the third light source 68 and light-receptiontime of the third light receiving unit 72, and, at the same time,information of the distance in the X-axis direction is acquired fromabsolute positional coordinates of the third light source 68 and thethird light receiving unit 72.

Next, a method of acquiring positional information in a Z-axis directionwill be explained with reference to FIG. 8. A plurality of units 80(shown as 80, 81 and 82 in the drawing) that perform sensing for thepositional information in the X-axis direction and the Y-axis directionexplained with reference to FIG. 7 are arranged in the Z-axis direction(a deep direction from the steering 43 toward the windshield glass 6).When the finger of the user (such as the driver) moves from the leftside to the right side on the sensing apparatus 51 in the drawing, alight flux φ8 from a specific light source 60 of the first unit 80 isconverted first to a substantially-collimated light flux, is reflectedby the moving finger of the user, is collected to become a reflectivelight flux φ7 by a light-collection lens element (not illustrated), andreaches a light receiving unit (not illustrated). At this stage, by theabove-described operation of the unit, time (absolute time T1) taken forpassage through the first unit 80 and the X-Y coordinates are madeclear. As similar to the second unit 81, when the finger of the userfurther moves from the left side to the right side, time (absolute timeT2) taken for passage through the second unit 81 and the X-Y coordinatesare made clear. Since a light flux φ11 of the third unit 82 does notblock the finger of the user as shown in FIG. 8, the finger position inthe Z-axis direction can be also identified.

Further, a moving speed and an acceleration of the finger in the Z-axisdirection of the spatial axis can be calculated from temporal differencebetween the absolute time T1 and the absolute time T2 and a sensingoutput (the X-Y coordinates and absolute time taken for acquiring thereflection light reflected from the finger by the light-reception unit)of the second unit 81. Similarly, a moving direction and an accelerationof the finger is also calculated from the sensing information of thefirst unit 80 and the second unit 81, so that not only the simplepositional information but also a user's will (such as stronger will ina larger acceleration) can be reflected on an information displayamount, speed and position of a system and others.

Note that the above-described configuration of the spatial sensingapparatus has been disclosed in, for example, Japanese PatentApplication Laid-Open Publication (Translation of PCT Application) No.2012-518228 and others. Also, in a market, a spatial sensing apparatusnamed as “AIRBAR (registered trademark: Neonode Inc.)” has beenmerchandised, and is known as the one that makes a PC have the touchpanel function when being simply placed. This spatial sensing apparatushas a bar shape, and therefore, can be easily arranged at a desirableposition even when being placed on an instrument panel or a dashboardinside a small car.

Note that the spatial sensing apparatus 53 corresponding to the imagedisplay region 1 (a) in FIG. 3 or the image display region 1(b) in FIG.4 has been described above in detail. However, the image display region2(a) in FIG. 3 or the image display region 2(b) in FIG. 4 as well as theimage display region 3(a) in FIG. 3 or the image display region 3(b) inFIG. 4 are described as similar to the above description. For those whoare skilled in the art, it would be clear that this manner can achievethe so-called interactive function that is the input of the positionalinformation corresponding to a desirable position of the screeninformation to make an instruction by the movement of the finger orothers to the desirable position of the screen information in thespatial region shown with the dashed line A while the user views thescreen information displayed on the forward part, in other words, thatis the operation in the mode allowing the user to have the interactionwhile viewing the projected screen.

Other Feature of Present Working Example

As shown in FIG. 9, the windshield glass 6 of the car has a curvatureradius “Rv” in a vertical direction and a curvature radius “Rh” in ahorizontal direction that are different from each other, and a relationof “Rh>Rv” is generally established. Therefore, as shown in FIG. 9, whenthe windshield glass 6 is regarded as the reflection surface, thewindshield glass 6 becomes a toroidal surface of the concave mirror.Therefore, in the HUD apparatus 100 of the present working example, theshape of the concave mirror 1 may have an average curvature radius thatis different between the horizontal direction and the vertical directionso as to correct a virtual-image magnification depending on the shape ofthe windshield glass 6, that is, correct the difference in the curvatureradius between the vertical direction and the horizontal direction ofthe windshield glass. In this case, the shape of the concave mirror 1 asa spherical or aspherical shape (expressed by an expression (2) below)that is symmetrical across the optical axis is expressed by a functionof a distance “h” from the optical axis, and a horizontalcross-sectional shape and a vertical cross-sectional shape of each ofdistant regions cannot be individually controlled, and therefore, theshape is preferably corrected so as to follow a function of planecoordinates (x, y) from the optical axis of the mirror surface so as tobe a free curved surface expressed by an expression (1) described below.

$\begin{matrix}{\left\lbrack {{Numerical}\mspace{14mu} {Expression}\mspace{14mu} 1} \right\rbrack \mspace{475mu}} & \; \\{Z = {\frac{c \cdot \left( {x^{2} + y^{2}} \right)}{1 + \sqrt{1 - {\left( {1 + K} \right){c^{2} \cdot \left( {x^{2} + y^{2}} \right)}}}} + {\sum{\sum\left( {{C_{j}\left( {m,n} \right)} \times x^{m} \times y^{n}} \right)}}}} & (1) \\{\left\lbrack {{Numerical}\mspace{14mu} {Expression}\mspace{14mu} 2} \right\rbrack \mspace{475mu}} & \; \\{Z - \frac{c \cdot h^{2}}{1 + \sqrt{1 - {\left( {1 + K} \right)c^{2}h^{2}}}} + {A \times h^{4}} + {B \times h^{6}} + {C \times h^{8}} + {D \times h^{10}} + {E \times h^{12}} + {F \times h^{14}} + {G \times h^{16}} + {H \times h^{18}} + {J \times h^{20}}} & (2)\end{matrix}$

In this case, a symbol “z” is a sag amount on the coordinates (x, y)with reference to axes defining a plane, a symbol “c” is a curvature onan origin of the axes defining the plane, a symbol “K” is a conicconstant, and a symbol “Cj” is a coefficient.

Return to FIG. 1 again. For example, the lens element 2 and the lenselement 3 are further arranged as transmissive optical componentsbetween the image display apparatus 4 and the concave mirror 1 tocontrol an emission direction of the optical ray to the concave mirror,so that distortion is corrected in accordance with the shape of theconcave mirror 1, and besides, virtual-image aberration includingastigmatism caused by the above-described difference between thecurvature radius in the horizontal direction and the curvature radius inthe vertical direction of the windshield glass 6 is corrected.

Meanwhile, as shown in FIGS. 1 and 2, most of S-polarized waves of thelight flux from the sun 50 are reflected on the windshield glass 6 whilemost of components of the light flux entering the car are P-polarizedwaves. Therefore, in order to project the image on the lower portion ofthe windshield glass for overlapping the image with the foreground view,the projection optical apparatus 220 that allows the S-polarized lightflux to enter the MEMS element for the scan is used. In this case,another reason why the S-polarized waves are used for the image displayis that the S-polarized waves each has a high reflectance on thewindshield glass as shown in FIG. 10 since a tilt angle of thewindshield glass 6 is equal to or larger than 40 degrees that is large.

Further, another reasons are that the windshield glass 6 of the car hasthe curvature radius Rh in the horizontal direction and the curvatureradius Rv in the vertical direction that are different from each otheras shown in FIG. 9 and that the center of the image is different fromthe position of the driver who is the viewer (a position of the steering43 in FIG. 11) as shown in FIG. 11 across the center of the curvature inthe horizontal direction.

On the other hand, the above-described projection optical apparatus 220projects the image onto the windshield glass by allowing the MEMS toperform the scanning in the vertical and horizontal directions whileusing a laser light source, and a member having a property that has areflectance against the S-polarized waves different from a reflectanceagainst the P-polarized waves is contained in the image display region 2(a) on the lower portion of the windshield glass shown in FIGS. 2 and 3,or the member is applied, adhered or pasted on the glass surface insidethe car, so that the image light is effectively reflected to orient thepractical image to the viewer. More specifically, as a reflectanceagainst the S-polarized laser light in a visible-light range (380 nm to780 nm), a reflectance from about 10% shown as a property (1) to about20% shown as a property (2) on average is favorable as shown in FIG. 12,so that the image light is reflected on the reflection surface of thewindshield glass in contact with a room inside, and heads toward thedriver who is the viewer.

More specifically, the same effect may be provided by using a sheetobtained by laminating optical multi-layer films having theabove-described properties or laminating a plurality of sheets havingdifferent refractive indexes from one another, or surface asperity maybe formed on a sheet surface in order to cause a larger diffusionproperty in the horizontal direction of the windshield glass than adiffusion property in the vertical direction of the same.

Setting the above-described sheet reflectance to be high in anultraviolet region (shorter than 380 nm) and a near-infrared region(longer than 780 nm) leads to suppression of entrance of ultravioletrays and near-infrared rays into the car for achieving more comfortablecircumstances.

As described above, in addition to the above-described features, thepresent working example relates to an information display apparatus thatdisplays information onto a vehicle, and the information displayapparatus is configured so that the information display apparatusincludes the first information display apparatus that causes lightreflected on the windshield glass of the vehicle to display imageinformation of the virtual image, the second information displayapparatus that allows the MEMS element to scan the windshield glass withthe laser light to acquire the practical image, and the thirdinformation display apparatus that uses the instrument panel of thevehicle, so that the first information display apparatus includes thevirtual-image optical system that displays the virtual image onto theforward part of the vehicle by causing the windshield glass to reflectthe light emitted from the image display apparatus displaying the imageinformation, so that the second information display apparatus includesthe practical-image optical system that displays the practical imageonto the windshield glass by causing the scanning-type mirror element toperform the scanning with the laser light, so that the third informationdisplay apparatus includes the direct-type image display apparatus asthe instrument panel, and so that the image display position of thefirst information display apparatus is set to the portion near thecenter of the windshield glass while the image display position of thesecond information display apparatus is set to the lower portion of thewindshield glass.

In this manner, the information display apparatus that reduces thepoint-of-view motion of the driver to contribute to the safety drivingassistance can be provided by the display combination among the HUDapparatus that overlaps the virtual image with the background view, thepractical-image display apparatus that displays the practical imageoverlapped with the foreground view, and the instrument panel.

Further, more specific optical configuration of the HUD apparatusincluding the virtual-image optical system of the information displayapparatus will be described below.

FIG. 13 is an entire configuration diagram of the HUD apparatus 100 inthe present working example. In FIG. 13, the concave (free-curved)mirror 1 that projects the image light for use in forming the virtualimage through the windshield glass 6, the correction lens group 2 foruse in correcting the distortion and the aberration caused in theprojection, the image display apparatus 4, and the backlight source 10configuring the backlight are provided in an order from a downstreamside. Note that a numerical symbol “7” indicates a housing. Further, inorder to suppress the P-wave components of the sunlight entering the HUDapparatus 100, an optical means 3 for use in suppressing the P-wavecomponents are provided as one example between the lens group 2 and theimage display apparatus 4.

First, in the present working example, the concave (free-curved) mirror1 that projects the image light preferably has a function of reflectingthe visible light (wavelength: about 400 to 700 nm), and besides,removing, for example, particularly the infrared rays (IR), theultraviolet rays (UV) and others, that are unnecessary for theinformation display apparatus and damage on the apparatus, from thesunlight containing various wavelength spectra. In this case, when thereflectance of the visible light is set to be equal to or higher than95%, a virtual-image optical system having a high light use efficiencyis achieved.

However, on the other hand, a case of direct looking at the concave(free-curved) mirror 1 through the windshield glass reduces dignity ofthe car since external light is reflected to cause bright view, reducesan image quality such as a contrast performance of the image (virtualimage) acquired in the information display apparatus since intensivelight such as the sunlight or a headlight of an oncoming car at night isreflected on the concave mirror 1 so that a part of the light raysreturns to a liquid crystal panel, and damages a polarization plate andthe liquid crystal panel configuring the image display apparatus 4.Therefore, when the reflectance of the concave (free-curved) mirror 1 ispurposely reduced to be equal to or lower than 90%, more preferably,equal to or lower than 85%, the above-described problems can be solved.

As a concave mirror supporting portion 1 a that is a base member of theconcave (free-curved) mirror 1, a high-transparent member is selected inorder not to allow the base member to absorb the above-described lighthaving the non-reflected wave-length component of the sunlight. As aplastic-made high-transparent member, (1) ZEONEX produced by Zeoncorporation, (2) polycarbonate, (3) acrylic resin and others are cited.The (1) ZEONEX having a moisture absorption rate of almost 0% and a highthermal deformation temperature is suitable but expensive, andtherefore, it is preferable to use a devised polycarbonate having thesimilar thermal deformation temperature and a moisture absorption rateof about 0.20. The acrylic resin having the highest formability andbeing inexpensive has the highest moisture absorption rate, andtherefore, it is essential to arrange a moisture proof film and areflection film.

In order to prevent the moisture absorption of the base member of theconcave (free-curved) mirror 1, in accordance with the reflection filmformed on the reflection surface, the moisture proof film may bearranged on an opposite surface by depositing SiN (silicon nitride)thereon as the moisture proof film. Since the SiN film that is themoisture proof film transmits the sunlight, the light absorption on thebase member does not occur, so that the thermal deformation can besuppressed. As a result, the shape change of the concave (free-curved)mirror made of the polycarbonate or the acrylic resin due to themoisture absorption can be also prevented.

Further, although not illustrated here, a light-transmitting platehaving a function of removing the IR and the UV may be arranged on anopening 41 formed above the HUD apparatus 100 in addition to or in placeof the concave (free-curved) mirror 1 having the function ofsuppressing/removing the IR and the UV. In this case, note that theprevention of external dusts from entering the HUD apparatus 100 can beachieved in addition to the provision of the IR- and UV-suppressionfunction.

As described above, by the concave (free-curved) mirror 1, theunnecessary components of the sunlight having a lot of spectrumcomponents entering the HUD apparatus 100 through the opening 41 can beremoved in the HUD apparatus 100, and the visible-light componentthereof can be mainly selectively extracted.

Meanwhile, as a factor reducing the image quality of the HUD apparatus,it is known that the image quality is reduced since the image light raysemitted from the image display apparatus 4 toward the concave mirror 1is reflected on a surface of the optical element 2 arranged in themiddle, and then, returns to the image display apparatus, is reflectedagain, and is overlapped with the original image light. Therefore, inthe present working example, it is preferable not only to suppress thereflection by depositing a reflection preventing film on the surface ofthe optical element 2 but also to design a limited lens surface shape ofeither one or both of image-light incident surface and exit surface ofthe optical element 2 so that the above-described reflection light isavoided from extremely collecting on only one part of the image displayapparatus 4.

Next, when a liquid crystal panel having a polarizing plate arranged inorder to absorb the reflection light emitted from the optical element 2is used as the image display apparatus 4, the reduction in the imagequality can be suppressed. A backlight source 10 of the liquid crystalpanel is controlled to orient an incident direction of the lightentering the image display apparatus 4 so that the light efficientlyenters an entrance pupil of the concave mirror 1. Further, a solid-statelight source having a long product lifetime may be adopted as the lightsource, and besides, the polarized-light conversion is preferablyperformed by using a PBS (Polarizing Beam Splitter) in which an opticalmeans for reducing a divergence angle of the light is provided as an LED(Light Emitting Diode) having small light output change againstvariation in an ambient temperature.

The polarizing plate is arranged at a position closer to the backlightsource 10 (the light incident surface) and a position closer to theoptical element 2 (the light exit surface) in the liquid crystal panelto increase a contrast ratio of the image light. When an iodine-basedmaterial having a high polarization degree is used for the polarizingplate at the position closer to the backlight source 10 (the lightincident surface), a high contrast ratio can be obtained. On the otherhand, when a dye-based polarizing plate is used at the position closerto the optical element 2 (the light exit surface), high reliability canbe obtained even if the external light enters or even if the ambienttemperature is high.

In the case of the usage of the liquid crystal panel as the imagedisplay apparatus 4, particularly when the driver wears polarizedsunglasses, a specific polarized wave is blocked, and failure of animage to be visible occurs. In order to prevent this, it is preferableto arrange a Δ/4 plate at a position closer to the optical element ofthe polarizing plate arranged at the position closer to the opticalelement 2 of the liquid crystal panel so as to convert the image lightunified in a specific polarizing direction into circular polarizedlight.

Further, a more specific optical configuration of the projection opticalapparatus having the practical-image optical system of the informationdisplay apparatus will be described.

FIG. 14 is a basic configuration diagram of a projection opticalapparatus 220 that acquires the practical image by causing the MEMS toperform the scanning with the laser light in the present workingexample. In FIG. 14, the projection optical apparatus 220 is ascanning-type image display apparatus that mounts an optical scanningapparatus performing scanning in a two-dimensional direction with thelaser light having been modulated in a light intensity (referred to as“modulated” below) in accordance with the image signal, and that causesthis optical scanning apparatus to scan an irradiation-receiving body(such as the windshield glass) with the laser light to portray theimage. That is, when the laser light from a light source unit 94 (94 a,94 b) is reflected by a scanning mirror 91 having a rotational axis, thescanning with the laser light can be performed. Conceptually, modulatedpixels 201 are two-dimensionally scanned on an image plane along alaser-light scan track 202 of a display surface 20.

Details of a two-dimensional polarizing function of the scanning mirror91 in the present working example will be described below.

FIG. 15 is a schematic configuration diagram of the scanning mirror 91that is a biaxial-driving MEMS element in the present working example.In the drawing, a scanning mirror surface 91 a that polarizes the laserlight at a reflection angle is connected to parts of a first torsionspring 91 b that are coaxially opposed to each other so as to sandwichthe scanning mirror surface 91 a therebetween. Further, the torsionspring 91 b is connected to a supporting member 91 c, and the supportingmember 91 c is connected to a second torsion spring 91 d. The secondtorsion spring 91 d is connected to a frame 91 e. And, although notillustrated, a permanent magnet and a coil are arranged at positionsthat are substantially symmetrical to each other across each of thetorsion springs 91 b and 91 d. The coil is formed at a position that issubstantially parallel to the scanning mirror surface 91 a of thescanning mirror 91, and generates a magnetic field that is substantiallyparallel to the scanning mirror surface 91 a when the scanning mirrorsurface 91 a of the scanning mirror 91 is in a stop state. When electriccurrent flows in the coil, the Lorentz force that is substantiallyvertical to the scanning mirror surface 91 a is generated on the basisof the Fleming's left-hand rule.

The scanning mirror surface 91 a rotates to reach a position at whichthe Lorentz force and restoring force of the torsion springs 91 b and 91d are balanced to each other. For the torsion spring 91 b, the scanningmirror surface 91 a resonates when an alternate current is supplied tothe coil at a resonance frequency of the scanning mirror surface 91 a.Similarly, for the torsion spring 91 d, the scanning mirror surface 91a, the torsion spring 91 b and the supporting member 91 c resonate whenan alternate current is supplied to the coil at a resonance frequency ofcombination of the scanning mirror surface 91 a and the supportingmember 91 c. In this manner, the resonance operations at the differentresonance frequencies in two directions are achieved.

In FIG. 16, when a rotational angle of the scanning mirror 91 that isthe reflection surface of the optical scanning unit is set to “β/2”, ascan angle that is an angle of the reflected optical rays changes by βthat is twice the rotational angle. In this case, if no optical elementis arranged between the scanning mirror 91 and an image plane 20, thescan angle β is equivalent to an incident angle “α” on the image plane20. Therefore, a size of the scanned image for a certain projectiondistance is undesirably defined by the rotational angle β/2 of thescanning mirror 91. Therefore, in the present working example, in orderto obtain a large screen for a short distance, an optical system (aconcave lens or a convex mirror) is provided (but not illustrated)between the scanning mirror 91 shown in FIG. 14 and the windshield glassthat is the projection surface, so that the above-described scanningamplitude is increased.

In the present working example, the distance from the viewer to theimage is short because the image is overlapped with the foreground viewviewed by the viewer, and therefore, it is necessary to set an imagedisplay region in the horizontal direction to be larger than that in thevertical direction. Accordingly, the inventors and others have obtainedan optimum value of an image display width through practical measurementwhile fitting 1.2 m to the fixed distance from the driver who is theviewer to the lower portion of the windshield glass. The inventors havefound out that it is necessary to set the display range in thehorizontal direction to be equal to or larger than 30 inches in order todisplay the left/right turn of the driven car by using an arrow inaccordance with the rotational angle of the steering, and have found outthat more favorable image display is achieved when display having adisplay range over 40 inches is achieved.

On the other hand, the inventors and others have found out that cleardisplay is achieved when the display range in the vertical direction is10 inches. Further, while it is necessary to increase the display rangeup to about 20 inches in order to enhance the visual recognition for thedisplay, the inventors and others have verified that an image that isenough on a practical level is obtained when an upper limit is set to 15inches since the increase in the amplitude in the vertical directionneeds to the decrease in the amplitude in the horizontal direction inthe driving of the MEMS.

Next, a first scanning state of the laser light scanning the image planein the present working example will be described.

FIG. 17 shows the first scanning state of the laser light emitted fromthe optical scanning unit in the present working example. As describedabove, regarding the scanning range (amplitude) of the optical scanningunit in the present working example, an amplitude angle in thehorizontal direction is set to be twice or more an amplitude angle inthe vertical direction so that the image display range in the horizontaldirection is larger than that in the vertical direction. A size of thelaser light on the windshield glass is set to be one pixel, thewindshield glass is scanned with the laser light 301 rightward from aleft side in the horizontal direction, and then, is scanned from theright side to the left side after a scanned line is moved down by onepixel. A numerical symbol 302 indicates the scan track of the firstscanning unit. A frame rate at which the image is switched may be 1/60Hz when the driving speed of the car is 40 km/hour. However, by settingthe frame rate to 1/120 Hz when the driving speed is 100 km/hour, arewriting speed of the display image is increased in accordance with thedriving speed of the car so that the optimal display is achieved.

In this case, as shown in an expression (3), the optical scanning unitin the present working example has a substantially constant value “A” asa product of a frame frequency “F”, a horizontal-polarization frequency“fh” and a vertical-polarization frequency “fv”. Therefore, the framerate is changed on the basis of the driving speed information of the caracquired from the driving assistance ECU 62 shown in FIG. 1 so that thehorizontal-polarization frequency is decreased, and the polarizationangle is proportionately decreased on the basis of the expression (3).

[Numerical Expression 3]

A=F(fh×fv)  (3)

As a result, although the horizontal-direction size of the image displayis small as the image display range, the information display apparatusthat does not cause the uncomfortableness in the usage can be obtainedsince a field of view of the driver is narrowed when the driving speedis high.

In the first scanning state in the present working example, single-colorlaser light of three colors (red color (635 nm), green color (532 nm)and blue color (460 nm)) shown in FIG. 18 is used. FIG. 20 shows resultsof conversion of chromaticity in single-color light case and a synthesiscase acquired in combination of the colors into coordinates onchromaticity diagram shown in FIG. 19, and shows that sufficientbrightness has been obtained while covering a display color range of anNTSC mode since a chromatic purity of each single color is excellent.

Further, mixture of different-color light at the time of emission ofeach single color, such as the mixed-color light in a case of 100%emission of the blue-color laser light mixed with 10% of the maximumlight emission of the green-color light at the same time as 5% of themaximum light emission of the red-color light causes a color that isequivalent to the blue color, and causes brightness that is twice ormore. As described above, it has been also found out that the scanningunit of the mode of the present application can further improve thebrightness of the virtual single-color light by using mixture of thedifferent-color laser light instead of using the single-color laserlight.

Next, a second scanning state of the laser light scanning the imageplane in the present working example will be described.

FIG. 21 shows the second scanning state of the laser light emitted fromthe optical scanning unit in the present working example. A differencefrom the first scanning state is that a plurality of optical scanningunits, that is, two optical scanning units that are the first scanningunit and the second scanning unit in FIG. 21 are arranged. Regarding thescanning range (amplitude) of the first scanning unit, the amplitudeangle in the horizontal direction is set to twice the amplitude angle inthe vertical direction or more so that the image display range in thehorizontal direction is larger than that in the vertical direction. Asize of the laser light 301 on the windshield glass is set to be onepixel, the windshield glass is scanned in the horizontal direction withbeam, in other words, it is scanned from the left side to the right sidealong a track shown by a solid line in FIG. 21, and then, is scannedfrom the right side to the left side after a scanned line is moved downby one pixel. A numerical symbol 302 indicates the scan track of thefirst scanning unit.

On the other hand, regarding the scanning range (amplitude) of thesecond scanning unit, the amplitude angle in the horizontal direction isset to twice the amplitude angle in the vertical direction or more assimilar to the first scanning unit so that the image display range inthe horizontal direction is larger than that in the vertical direction.A size of the laser light 303 on the windshield glass is set to be onepixel, the windshield glass is scanned in the horizontal direction withbeam, in other words, it is scanned from the right side to the left sidealong a track shown by a dashed line in FIG. 21, and then, is scannedfrom the left side to the right side after a scanned line is moved downby one pixel. Note that FIG. 21 shows a state in which the laser light303 arrives at the last pixel on the lowest line. The scanning performedby the second scanning unit may be performed from an upper side to alower side, or from the lower side to the upper side. A numerical symbol304 indicates a scan track of the second scanning unit. In this case, animage of a next frame is displayed so that display of a next frame ofthe frame image that is displayed by the first scanning unit shifts byalmost ½ frame.

As a result, the inventors have found out that the frame rate can bevirtually twice. Further, in the first scanning unit in the secondscanning state, single-color laser light of three colors that are redcolor (635 nm), green color (532 nm) and blue color (460 nm)) shown inFIG. 22 is used. And, when single-color laser light of three colors thatare red color (645 nm), green color (515 nm) and blue color (450 nm)shown in FIG. 22 is used in the second scanning unit, speckle can bealso reduced. And, regarding chromaticity in single-color light case anda synthesis case acquired in combination of the colors, sufficientbrightness has been obtained while covering the display color range ofthe NTSC mode since a chromatic purity of each single color of the laserlight source configuring the two scanning unit is excellent as shown inFIG. 23.

The mixture of the different-color light at the time of the single-colorlight emission from each of the first scanning unit (referred to as (1)below) and the second scanning unit (referred to as (2) below), such asthe mixed-color light, causes a color that is equivalent to the bluecolor, and causes brightness that is twice the brightness of the non-mixcolor light or more, the mixed-color light being generated in a case of100% emission of the blue-color laser light (1) and (2) from the twoscanning unit mixed with 5% of the maximum light emission of thegreen-color light (1) at the same time as 10% of the maximum lightemission of the green-color light (2) and 5% of the maximum lightemission of the red-color light (1).

As described above, it has been found out that the present workingexample can further improve the brightness of the virtual single-colorlight by using the mixture of the different-color laser light instead ofusing the single-color laser light even when the plurality of scanningunits are used to be overlapped. In the present working example, theeffect of the case of the simultaneous usage of the two scanning unitshas been described. However, it is needless to say that simultaneoususage of three or more scanning units can virtually increase the framerate, and speckle noises can be also significantly reduced by the usageand the overlap of the laser light having different wavelengths from oneanother for the respective scanning units. The brightness can be alsoimproved without losing the single-color chromaticity as describedabove.

Subsequently, a more specific configuration of the display using theinstrument panel that is the above-described information displayapparatus will be described.

The instrument panel 42 shown in FIG. 1 is arranged on an inner radialportion of the steering 43, and therefore, the displayed image causesthe largest point-of-view motion of the driver who is the viewer. Thus,except in the automatic driving of the car using the automatic drivingmode, information having low urgency is displayed. When the point ofview of the driver is sensed by the above-described viewing camera 210to change the display image, a lot of image information can beeffectively displayed for the driver.

In order to thin the apparatus, a liquid crystal panel is used as theinstrument panel. A curved surface may be applied in importantconsideration of interior design of the car. When the display content isswitched at a high speed so that the display speed is 120 Hz that istwice the frame rate (60 Hz) or 240 Hz that is four times the framerate, real-time display of the image information or others from theviewing camera outside the car is achieved.

The above-described information display apparatus has the image displayregion 1(a), the image display region 2(a) and the image display region3(a) as three types of the information display positions as shown inFIG. 3. On the other hand, for example, the viewing camera 210 shown inFIGS. 1 and 2 is used as a sensor for use in viewing the point-of-viewmotion of the driver who is the viewer. In this manner, in response tothe information of the point-of-view motion of the viewer and the speedof the car, the respective images displayed at the three types of theinformation display positions are displayed in combination for optimalposition, time and displayed content, so that the information displayapparatus that is effective for the safety driving assistance can beprovided. For example, control for change of the information displaypositions in a turning direction or others is performed in accordancewith the point-of-view motion of the viewer at the time of the turning.

When display centers of the above-described three information displaypositions are arranged near a line including a rotational center axis ofthe steering, right and left point-of-view motions of the driver who isthe viewer in the horizontal direction are equalized to each other, andtherefore, an effect that suppresses the tiredness in the driving and aneffect that minimizes the point-of-view motion can be obtained.

The information display apparatuses according to the various workingexamples of the present invention have been described above. However,the present invention is not limited to the above-described workingexamples, and include various modification examples. For example, in theabove-described working examples, the entire system has been explainedin detail for easily understanding the present invention, and theworking examples are not always limited to the one including allstructures explained above. Also, a part of the structure of one workingexample can be replaced with the structure of another working example,and besides, the structure of another working example can be added tothe structure of one working example. Further, another structure can beadded to/eliminated from/replaced with a part of the structure of eachworking example.

EXPLANATION OF REFERENCE CHARACTERS

1 . . . concave mirror, 1 a . . . concave-mirror supporting unit, 2 and3 . . . optical element (lens), 4 . . . image display apparatus, 6 . . .projection-receiving member (windshield glass), 8 . . . eyebox (eyes ofviewer), 10 . . . backlight source, 20 . . . display surface, 41 . . .opening, 42 . . . instrument panel, 43 . . . steering, 44 . . .windshield cover, 45 . . . vehicle body, 50 . . . sun, 51, 52 and 53 . .. spatial sensing apparatus, 531 . . . converting apparatus, 60 . . .light source, 61 . . . capacitor optical element, 65 . . .light-collecting lens element, 64 . . . light receiving unit, 80 . . .sensing unit, 91 . . . scanning mirror, 100 . . . HUD apparatus, 101 . .. car, 201 . . . pixel, 202 . . . scan track of laser light, 210 . . .viewing camera, 220 . . . projection optical apparatus, 301 . . . laserlight from first scanning unit, 302 . . . scan track of first scanningunit, 303 . . . laser light from second scanning unit, 304 . . . scantrack of second scanning unit, 1(a), 2(a), 3(a), 1(b), 2(b) and 3(b) . .. image display region

1. An information display apparatus displaying information onto avehicle comprising: an information display apparatus configured todisplay image information onto an image display region on a forward partof a driver seat of the vehicle; and a spatial sensing means configuredto detect positional information of instruction made by a driver in aspatial region between the driver seat and the displayed image displayregion, wherein the information display apparatus includes a meansconfigured to display the instruction made by the driver onto the imagedisplay region on the forward part in response to the positionalinformation of the instruction made by the driver, detected by thespatial sensing means.
 2. The information display apparatus according toclaim 1, wherein the information display apparatus includes avirtual-image optical system configured to display a virtual image ontothe forward part of the vehicle by allowing the windshield glass toreflect light emitted from the image display apparatus.
 3. Theinformation display apparatus according to claim 2, wherein theinformation display apparatus is arranged on a dashboard between thewindshield glass and the driver seat.
 4. The information displayapparatus according to claim 1, wherein the information displayapparatus includes a practical-image optical system configured todisplay a practical image by scanning the windshield glass of thevehicle with light emitted from the information display apparatus. 5.The information display apparatus according to claim 4, wherein theinformation display apparatus is arranged on a dashboard between thewindshield glass and the driver seat.
 6. The information displayapparatus according to claim 1, wherein the information displayapparatus includes a direct-view type image display apparatus using aninstrument panel of the vehicle.
 7. The information display apparatusaccording to claim 6, wherein the information display apparatus isarranged between the instrument panel and the driver seat.
 8. A spatialsensing apparatus for achieving the information display apparatusaccording to claim 1, wherein a plurality of a pair of optical elementsmade of a light emitting element and a light-collecting lens element arelinearly arranged, the light emitting element creating a collimatedlight flux from a light flux emitted from a light source, and thelight-collecting lens element receiving a reflected light flux of thelight flux from the light emitting element, the reflected light fluxbeing reflected on obstacles.
 9. The spatial sensing apparatus for theinformation display apparatus according to claim 8, wherein theplurality of the pair of optical elements are arranged between thewindshield glass and the driver seat in a horizontal direction that isbesides a direction that is orthogonal to a direction from the driverseat to the windshield glass.
 10. The spatial sensing apparatus for theinformation display apparatus according to claim 8, wherein theplurality of the pair of optical elements are arranged along at leastone side of an instrument panel of the vehicle.